1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a combined machine of these, and more particularly to a discriminating technique of a cartridge detachably attached to a main body of the image forming apparatus.
2. Description of the Related Art
Conventionally, there is widely known an image forming apparatus in which part of its structural components is made a cartridge so that it can be easily exchanged and handled. For example, in the image forming apparatus of an electrophotographic system, there is known an apparatus in which an image supporting body, an electrifying unit, a developing unit, a cleaning unit, and the like are integrated into one structure and are made a cartridge, or only a toner of powder is made a cartridge. A user exchanges the cartridge and uses it.
As the cartridge, in order to assure the picture quality or life of the image forming apparatus, it is desirable to use the cartridge whose structure and specification conform to the main body of the image forming apparatus, a so-called authorized product.
On the other hand, actually, a cartridge made by a so-called third party, which has compatibility with the cartridge of the authorized product, is put on the market. The structure and specification of the cartridge made by the third party do not necessarily conform to the main body of the image forming apparatus, and according to circumstances, the expected picture quality or life can not be achieved, and the merits of a user or maker can be damaged.
Then, conventionally, there have been proposed techniques to discriminate the conformity between the main body of the image forming apparatus and the cartridge. For example, Japanese Patent Unexamined Publication No. Hei. 7-152307 proposes a technique to electrically discriminate the kinds of cartridges through ON/OFF of a switch. Japanese Patent Unexamined Publication No. Hei. 9-185311 proposes a technique to discriminate the kinds of cartridges through a rugged pattern. And then, it is devised such that the kinds of cartridge are discriminated by these techniques, and if an unsuitable cartridge is loaded in the main body of the image forming apparatus, the image forming apparatus can not be used.
However, when the techniques are applied and the mechanical compatibility of many cartridges is judged, there are problems that the electric circuit becomes complicated or the rugged pattern becomes large. On the other hand, in recent years, although the manufacture of image forming apparatuses through OEM (Original Equipment Manufacturing) is popular, since there is a request by a partner maker to make the cartridges of the respective rival makers incompatible with each other, the kinds of cartridges to be discriminated are increasing.
The present invention has been made in view of such circumstances and provides an image forming apparatus which can discriminate the kinds of many cartridges through a small and simple structure.
That is, according to an aspect of the present invention, an image forming apparatus includes an image forming apparatus main body, a cartridge detachably attached to the image forming apparatus main body, and a discriminating unit which discriminates the mechanical compatibility between the cartridge and the image forming apparatus main body, in which the discriminating unit includes a first discriminating unit which discriminates the mechanical compatibility by defining a positional relation between a fitting portion provided at a predetermined position at a side of the cartridge and a fitted portion provided at a predetermined position at a side of the image forming apparatus main body in a loaded state on a fitting surface according to characteristics of the cartridge and characteristics of the image forming apparatus main body, and a second discriminating unit which discriminates the mechanical compatibility by defining a positional relation between the fitting portion and the fitted portion in the loaded state in a fitting direction according to the characteristics of the cartridge and the characteristics of the image forming apparatus main body.
As a mode of the first discriminating unit of the image forming apparatus, the first discriminating unit may include plural first concave portions provided at the side of the image forming apparatus main body, a switch button provided as the fitted portion in one of the plural first concave portions according to the characteristics of the image forming apparatus main body, and a first convex portion provided as the fitting portion at the side of the cartridge and being capable of fitting to one of the plural first concave portions provided at the side of the image forming apparatus main body according to the characteristics of the cartridge. Although the switch button can be provided at the side of the cartridge, since the structure of the cartridge is complicated and the cost is raised, it is preferable to provide the switch button at the side of the image forming apparatus.
Besides, in the first concave portions and the first convex portion as described above, the first concave portions are slit holes of long length in an attaching/detaching direction of the image forming apparatus main body and the cartridge, and the first convex portion is a projecting portion of long length in the attaching/detaching direction of the image forming apparatus main body and the cartridge.
By constructing the image forming apparatus in this way, with the attaching/detaching operation between the image forming apparatus main body and the cartridge, the first convex portion and the first concave portion become easy to fit. Further, the first convex portion and the first concave portion become difficult to damage at the time of attachment/detachment.
Besides, in the present invention, the second discriminating unit includes a main body side second concave-convex portion provided at the side of the image forming apparatus main body according to the characteristics of the image forming apparatus main body, and a cartridge side second concave-convex portion provided at the side of the cartridge according to the characteristics of the cartridge, and at least in a case where the characteristics of the image forming apparatus main body and the cartridge are coincident with each other, both the second concave-convex portions are fitted to each other.
According to whether the main body side second concave-convex portion and the cartridge side second concave-convex portion are fitted or not, two modes are defined with respect to the positional relations between the fitting portion and the fitted portion in the fitting direction in the loaded state, and it is possible to discriminate the mechanical compatibility between the image forming apparatus main body and the cartridge.
Incidentally, the statement xe2x80x9cat least in a case where the characteristics of the image forming apparatus main body and the cartridge are coincident with each other, both the second concave-convex portions are fitted to each otherxe2x80x9d means that even in the case where both the characteristics are not coincident with each other, there can be a case where both the second concave-convex portions are fitted. Even in that case, by the first discriminating unit, it is possible to discriminate the mechanical compatibility between the image forming apparatus main body and the cartridge.
In the second discriminating unit as described above, the main body side second concave-convex portion may be structured such that it can be freely retracted in a concave-convex direction with respect to the cartridge and is urged to the side of the cartridge.
By constructing the image forming apparatus in this way, even in the case where the main body side second concave-convex portion and the cartridge side second concave-convex portion are not fitted to each other, since the main body side second concave-convex portion is retracted to the side of the image forming apparatus main body against urging force, forcible force is not applied to both the second concave-convex portions, and there is no fear to damage both the concave-convex portions, the cartridge, and the image forming apparatus main body. In the case where the main body side second concave-convex portion and the cartridge side second concave-convex portion are fitted to each other, the urging force assists so that they become easy to fit, and when they are once fitted to each other, they become difficult to disengage.
Besides, in the second discriminating unit as described above, the plural first concave portions and the main body side second concave-convex portion may be integrally constructed.
By constructing the image forming apparatus in this way, in the case where the first concave portion and the first convex portion are fitted to each other, the urging force assists so that they become easy to fit, and when they are once fitted to each other, they become difficult to disengage.
Besides, the present invention relates to a cartridge of an image forming apparatus loaded in the image forming apparatus.